Fuels containing wear-reducing and rust preventing additives



United States Patent FUELS CONTAINING WEAR-REDUCING AND RUST PREVENTING ADDHTIVES John O. Smith, Jr., Swampscott, Mass, and John F. Kunc,

Jr., Union,'-N.J., assignors toEsso Research and Engineering Company, a corporation of Delaware No Drawinga Application November 8, 1957 i i Serial No. 695,218

10 Claims. (CI. 44-63) effective as rust reventives and load-carrying agents under extreme pressure.

It is well known that motor-fuels that are higher than normal in sulfur content will increase the low temperature Wear of piston rings over thatobtained with fuels of lower sulfur content. Because of this, it is normally necessary that such fuels be refined to a satisfactorily low sulfur content.

It is one object of the present invention to provide an additive mixture that will enable fuels of higher than normal sulfur content to be employed without the necessity for additional refining to remove the sulfur.

It is also an object of the invention to improve the wear performance of loW-sulfur-content fuels as Well.

' A' further object of the invention is to provide liquid fuels containing addition agents that will serve as rust inhibitors for the fuels when they come into contact with ferrous metals in the presence of moisture.

In accordance with the present invention, it has been found that engine wear can be decreased by incorporating into the fuel fed to the engine a minor proportion, be-

tweenabout 0.009% and about 0.9% by weight, and

preferably of the order of about 0.03 to about 0.3% by weight, offa composition consisting of a hydroquinoline and a phosphate of a mono ether of a poly alkylene glycol. At concentrations of 0.3 to 0.9%, the'additive of-the present invention is efliect ive as a solvent oil in gasoline. The proportion of the hydroquinoline compound to the phosphoric acid ester in the composition is in the range of about /2 to 2 parts of the former'to 1 part of the latter.

Among the hydroquinolines that may be used in this invention are included tetra hydroquinoline, decahydroquinoline, hyd'r'ocarbostyril', 'th'aIlineQdihydro trimethyl quinolines and 6-ethoxy, l,2-dihydro, 2,2,4-trimethyl quinoline.

- The phosphates that are employed in the present invention are the reaction products of mono ethers of polyalkylene. glycols'with P 0 These mono ethers are well known articles of commerce and are prepared by condensing an alkene oxide orepoxy alkane, like ethylene oxide or propylene oxide or mixtures thereof with an organic compound containing a hydroxyl group, e.g. an alcohol.

The mono ethers of polyglycols suitable to be converted to phosphates for use in accordance with the present invention are fully described in US. Patents 2,425,755 and 2,425,845. For example, by reacting 15.5 lbs. of

' having 40.5 Saybolt viscosity at 210 F.

The reaction between the polyglycol ether and the P 0 is conducted at temperatures between 80 .F. and 450 F. for periods of 0.1 to 10 hours. For example the desired amount of P 0 may be added slowly to the polyglycol ether with rapid stirring. The mixture may then be heated to the desired reaction temperature, say 300 to 350 F. for about 2 to 5 hours, preferably while bubbling nitrogen or other inert gas through the mixture to agitate the same and to prevent oxidation.

Specific examples of suitable glycol monoethers that can be reacted with P 0 to prepare the phosphates used in this invention include: n-tridecyl monoether of hexaethylene glycol, iso tridecyl monoether of nonapropylene glycol, n-butyl (dodeca isopropoxy) alcohol, and n-decyl (pentadeca butoxy) alcohol. Also included are monoethers of polyglycols wherein the polymeric chain may consist of different alkylene oxide groups, e.g. ethylene oxide and propylene oxide in the same chain. Actually, these products made by condensation of alkylene oxides are mixtures of monoethers 'of polyglycols of varying chain length. The assignment of .a formula such as .lS0-C1 H27( OC2H4) 9OH thus indicates that the average chain length in the mixture corresponds to nona-ethoxy. .The presence of monoethers ofpolyglycols of various chain lengths in the material which is converted to a phosphate for use in accordance with the present invention is immaterial so 1 long as the chain lengths lie within the limits outlined above or in the following paragraphs.

The phosphates of the present invention may also be characterized as the alkyl polyalkyleneoxy mono and diesters'of phosphoric acid having the following general formula:

[R 0 n'o .]-i 011 a-. V where R is an alkyl group of from 2 to 13 carbon atoms, R is an aliphatic hydrocarbon radical of from 2 to 8 carbon atoms, x is an integer from 8 to 18 and y is an integer from 1 to 2.

Particularly preferred are phosphates fitting the general formula:

The following examples serve to illustrate this invention: i

' EXAMPLE'I A quantity of butyl dodeca isopropoxy alcohol,

7 (EH: C4H0(0CH -CH)10OH obtained from propylene oxide and n-butyl alcohol, and having a Saybolt viscosity of 264 SSU at 210 F., was heated for 4 hours at 300 F. in the presence of 4 weight percent of P20 and the resulting product was filtered. Analysis of the product showed a phosphate content corresponding to the monophosphate. Some diphosphate and some unreacted butyl dodecapropoxy alcohol were also present. In two tests for load-carrying property under extreme pressure conditions, namely the well known Almen and S.A.E. tests used on lubricating oils, this product carried the full loads attainable in the test apparatus, respectively 16 weights and 460 pounds. The product was washed with water and the wash water gave a negative test for phosphate ion, thus proving the absence of free P or H PO in the product, since both of these compounds are freely soluble in water.

EXAMPLE 2 Three gasoline samples were prepared using a high octane gasoline containing 0.27% sulfur. One sample contained 0.1% of the normal butyl dodeca isopropoxy phosphate of Example 1; the second sample contained 0.2% of 6-ethoxy, 1,2-dihydro, 2,2,4-trimethyl quinoline; and the third sample contained 0.1% of the phosphate compound and 0.2% of the hydroquinoline compound. A fourth sample was prepared using the same additives, in the same concentrations, as in the third sample, but in a high octane gasoline of 0.02% sulfur content. Each of these four samples, as well as each of the samples of the gasolines without the additives mentioned were compared in replicate tests conducted as follows in a single cylinder Lauson spark ignited gasoline engine equipped with a radioactive top piston ring. Each test consisted of a series of five 5-minute runs with a 30 minute shutdown between each run. During the shutdown, cooling water was run through the jacket, bringing the jacket water-out temperature to 60 F. Each five minute run therefore began at 60 F. No cooling was used during the five minute run and the water-out temperature was allowed to reach its own level, which was 100i1 F. at the end of the run. Two series of runs were made each day, one a reference run on Reference fuel and the other a test run on Reference fuel plus the additive. Before either the reference or test run, the engine was run for five minutes on the fuel to be tested in order to wet-down the engine. These five minute wet-down runs were at a higher temperature than the series of cyclic five minute runs which constituted the reference or test runs. Following the Wet-down, there was a 30 minute shutdown after which the reference or test run began. Each run was made on a fresh charge of summer grade mineral oil containing no additives. A load of 1.6 b.kw. and a speed of 1800 rpm. were maintained throughout the program.

At the end of each run, the oil charge was drained and dip counted with a scintillation counter in order to determine the amount of iron which had been worn off the radioactive top compression ring into the crankcase lube oil. Each wear measurement was repeated at least six times and the results, given below in Table I, are significant at the statistical 95% confidence level.

Table I.Preventi0n of top ring wear caused by high sulfur content gaso ine l G-ethoxy, 1,2-dihydro, 2,2,4-tr1methyl quinoltue.

It will be noted from the data obtained that the high sulfur fuel, B, caused nearly twice as much wear as the low sulfur fuel, A, and that the additive mixture of the present invention when added to gasoline B decreased the wear to the level obtained when gasoline A was used without additives. Furthermore, even fuel A was substantially improved when the same additive was put in it.

Fuels A and B contained 2.5 cc. tetraethyl lead, introduced as Ethyl Fluid, per gallon. The two gasolines had end-points of about 390 F. as determined by ASTM Method D-86.

It will also be noted from the above data that the hydroquinoline compound alone was not at all effective in reducing ring wear but that it greatly enhanced the wearreducing effect of the phosphate ester.

EXAMPLE 3 The fuels of Test Numbers 2 and 5 in Example 2 were again tested as in Example 2, but with the engine having in its crankcase a commercial lubricating oil containing wear-preventive additives, instead of a plain mineral oil. The results are shown in Table II.

These data show that the efiect of the fuel additive of this invention in decreasing wear of piston rings in an engine is exerted even when the engine is lubricated with an oil containing lubricant additives that have some wearprevention property.

EXAMPLE 4 The additives of the present invention were tested for their rust preventive properties in. a virgin heating oil and in a JP-4 jet fuel by storing each of a number of samples of those fuels alone and containing various additives in contact with steel strips and in the presence of water for periods of 8 days at room temperature and then observing-the steel strips. In each case 10 cc. of water was added to a gram sample of the fuel or blend. The results obtained are presented in Tables III and IV. It will be noted that in the heating oil neither the phosphate additive alone nor the tetrahydroquinoline alone prevented rust or corrosion but that with both additives present corrosion and rust were prevented. Likewise in the jet fuel, corrosion'resulted with the phosphate additive alone but not when both the phosphate and the tetrahydroquinoline were present.

Table Ill.-Ruszing tests with virgin heating oil Table I V.Rusting tests with jet fuel Blend: Result JP-4 fuel alone Rust. JP-4 fuel+0.2% n-butyl dodeca isopropoxy phosphate Heavy corrosion. IP-4 fuel+O.1% n-butyl dodeca isopropoxy phosphate+0.1% tetrahydroquinoline Slight stain.

EXAMPLE 5 A commercial gasoline having about 10 lbs. Reid Vapor pressure and 380 F. end-point was tested for its rustpreventive property without and with the fuel additives of the present invention. The gasoline was stored over water, with polished steel strips immersed at the interface of the liquids. The results obtained after storage for two weeks are shown in Table V.

+02% n-butyl dodeca isopropoxy phosphate No'rust.

The following are representative examples of other compositions that may be employed in practicing the present invention. In each case, percentages are by weight. g

(l) A diesel fuel containing about 0.25% of decahydroquinoline+0.l5% of the reaction product of P and n-decyl (pentadecabutoxy) alcohol.

(2) A heating oil of No. 2 grade containing about 0.1% of tetrahydroquinoline and about 0.2% of iso-octyl octadeca ethoxy monophosphate.

(3) A JP5 jet fuel containing about 0.15%T of 6- ethoxy, 1,2-dihydro, 2,2,4-trimethyl quinoline and about 0.15% of the reaction product of P 0 and the 'isotridecyl monoether of nonapropylene glycol.

This invention is applicable to liquid petroleum fuels comprising a major proportion, at least 95%, of hydrocarbons boiling at temperatures up to 750 F. These fuels include gasoline, such as aviation, marine and automotive or motor gasolines, aviation turbo fuels, such as JP-l, JP-4and JP-S fuels, and diesel fuels such as marine, stationary and automotive diesel fuels.

Gasoline consists of at least 95 percent of a mixture of volatile hydrocarbons and may contain sulfur compounds as Well as various beneficiating additives, such as antiknock agents, scavenging agents, antioxidants, dyes, anti-icing agents and solvent oils in a total concentration of additives not exceeding 5 percent by weight. The volatility of gasoline is such that it has a vapor pressure between 5 and 15 lbs. per square'inch at 100 F. by ASTM Method D 32356 and a boiling range between 75 F. and

450 F. by ASTM Method D 86-56. Aviation gasolines a mixture of volatile hydrocarbons. It is defined by.U.S.

Military Specifications MIL-F-56l6 and MIL-F-5624C. Its volatility is such that its end-point does not exceed 572 F. Its viscosity is between 0.5 and 1.5 centistokes at 100 F Diesel fuel for use in accordance with the present invention consists of at least 95% of a mixture of hydrocarbons boiling between 250 F. and 750 F. by either ASTM Method D 86-56 when its end-point does not exceed 600 F. or ASTM Method D 158-54 when its viscosity exceeds 1.4 centistokes at 100 F. Diesel fuel is defined by the specifications of ASTM D 975-53T in grades No. 1D,

No. 2D and No. 4D, all of which are suitable for use in accordance with the present invention. They have viscosities between 1.4 and 26.4 centistokes at 100 F.

The liquid fuels for use in accordance with the present invention comprise at least 95 percent by weight of a mixture of hydrocarbons witha boiling range that lies within the limits of F. and 750 F. and with a viscosity within the limits of 0.264 and 26.4 centistokes at 100 F.

,While the present invention has been described with respect to certain specific embodiments, restriction to those embodiments is not intended. As previously stated, the compositions of the present invention comprise not only gasolines but diesel fuels as well, and middle .distillates as hereinbefore described. The scope of the invention is to be'limited only by the appended claims.

What is claimed is:

1. An-improved liquid fuel composition comprising a major proportion, at least by weight, of liquid hydrocarbons boiling within the limits of 75 F. and 750 F., and a minor proportion, between 0.03% and 0.9% by weight, of a mixture of a hydroquinoline selected from 'a group consisting of tetrahydroquinoline, decahydroquinoline, hydrocarbostyril, thalline, dihydrotrimethylquinoline, and 6-ethoxy, 1,2-dihydro, 2,2,4- trimethylquinoline and a phosphoric acid ester of a polyalkylene glycol monoether, wherein said phosphoric acid ester is defined by the formula:

where R is an alkyl group of from 4 to 8 carbon atoms, R" is selected from the group of H and CH 2: is an integer from 10 to 16, and y is an integer from 1 to 2, the ratio of the hydroquinoline to the said ester being in the range of from /2 part of 2 parts by weight of the hydroquinoline to 1 part of the ester.

2. A fuel composition as defined by claim 1, wherein the said hydroquinoline is tetrahydroquinoline.

3. A fuel composition as defined by claim 1, wherein the said hydroquinoline is decahydroquinoline.

4. A fuel composition as defined by claim 1, wherein the said hydroquinoline is hydrocarbostyril.

5. A fuel composition as defined by claim 1, wherein the said hydroquinoline is thalline.

6. A fuel composition as defined by claim 1, wherein the said hydroquinoline is dihydrotrimethylquinoline.

7.5 A fuel composition as defined by claim 1, wherein the said hydroquinoline is 6-ethoxy, 1,2-dihydro, 2,2,4- tr'imethylquinoline,

8. A fuel composition as defined by claim 1, wherein said phosphoric acid ester comprises n butyl dodeca isopropoxy monophosphate.

9. A fuel composition as defined by claim 1, wherein said phosphoric acid ester comprises iso-octyl octadeca ethoxy monophosphate.

10. A fuel composition as defined by claim 1, wherein said hydrocarbon fuel comprises gasoline, and wherein said mixture comprises 6-ethoxy, 1,2,-dihydro, 2,2,4-trimethylquinoline and n-butyl dodeca isopropoxy monophosphate.

References C i/adiin the file of this patent UNITED STATES PATENTS 2,030,033 McConnell Feb. 4, 1936 2,080,299 Benning et al. May 11, 1937 2,241,243 Conary et al. May 6, 1941 2,676,926 Smith et al. Apr. 27, 1954 2,831,861 Wilde Apr. 22, 1958 v I March 29 1960 John O. Smith JrG, et ale It is hereby certifiedthat error appears in t en't requiring correction and that is corrected below.

he above numbered pathe said Letters Patent should read as Column 6 from V part line 35, V for "from part of 2 parts" to 2 parts read Signed and sealed this' 18thday of July 1961.

" (SEAL) Attest: i ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents UNITED STATES PATENT OFFICE) CERTIFICATION OF CORRECTION Patent No 2,930,680 v March 29 1960 John 0., Smith Jra et aln It is hereby certified'that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 6 line 35 for "from V part of 2 parts read from V part to 2 parts ""a (SEAL) Attest:

ERNEST W. SWIDER Attesting Officer DAVID L. LADD Commissioner of Patents 

1. AN IMPROVED LIQUID FUEL COMPOSITION COMPRISING A MAJOR PROPORTION, AT LEAST 95% BY WEIGHT, OF LIQUID HYDROCARBONS BOILING WITHIN THE LIMITS OF 75*F. AND 750*F., AND A MINOR PROPORTION, BETWEEN 0.03% AND 0.9% BY WEIGHT, OF A MIXTURE OF A HYDROQUINOLINE SELECTED FROM A GROUP CONSISTING OF TETRAHYDROQUINOLINE, DECAHYDROQUINOLINE, HYDROCARBOSTYRIL, THALLINE, DIHYDROTRIMETHYLQUINOLINE, AND 6-ETHOXY, 1,2-DIHYDRO, 2,2,4TRIMETHYLQUINOLINE AND A PHOSPHORIC ACID ESTER OF A POLYALKYLENE GLYCOL MONOETHER, WHEREIN SAID PHOSPHORIC ACID ESTER IS DEFINED BY THE FORMULA: 